/*
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 *
 * This software is open source.
 * See the bottom of this file for the licence.
 */

package org.dom4j.tree;

import java.io.IOException;
import java.io.Serializable;
import java.io.Writer;
import java.util.List;

import org.dom4j.Document;
import org.dom4j.DocumentFactory;
import org.dom4j.Element;
import org.dom4j.Node;
import org.dom4j.NodeFilter;
import org.dom4j.XPath;
import org.dom4j.rule.Pattern;

/**
 * <p> <code>AbstractNode</code> is an abstract base class for tree
 * implementors to use for implementation inheritence. </p>
 * 
 * @author <a href="mailto:james.strachan@metastuff.com">James Strachan </a>
 * @version $Revision: 1.2 $
 */
public abstract class AbstractNode implements Node, Cloneable, Serializable
{
   protected static final String[] NODE_TYPE_NAMES =
      { "Node", "Element", "Attribute", "Text", "CDATA", "Entity", "Entity",
         "ProcessingInstruction", "Comment", "Document", "DocumentType",
         "DocumentFragment", "Notation", "Namespace", "Unknown" };

   /** The <code>DocumentFactory</code> instance used by default */
   private static final DocumentFactory DOCUMENT_FACTORY =
      DocumentFactory.getInstance();

   public AbstractNode()
   {
   }

   public short getNodeType()
   {
      return UNKNOWN_NODE;
   }

   public String getNodeTypeName()
   {
      int type = getNodeType();

      if((type < 0) || (type >= NODE_TYPE_NAMES.length))
      {
         return "Unknown";
      }

      return NODE_TYPE_NAMES[type];
   }

   public Document getDocument()
   {
      Element element = getParent();

      return (element != null) ? element.getDocument() : null;
   }

   public void setDocument(Document document)
   {
   }

   public Element getParent()
   {
      return null;
   }

   public void setParent(Element parent)
   {
   }

   public boolean supportsParent()
   {
      return false;
   }

   public boolean isReadOnly()
   {
      return true;
   }

   public boolean hasContent()
   {
      return false;
   }

   public String getPath()
   {
      return getPath(null);
   }

   public String getUniquePath()
   {
      return getUniquePath(null);
   }

   public Object clone()
   {
      if(isReadOnly())
      {
         return this;
      }
      else
      {
         try
         {
            Node answer = (Node) super.clone();
            answer.setParent(null);
            answer.setDocument(null);

            return answer;
         }
         catch(CloneNotSupportedException e)
         {
            // should never happen
            throw new RuntimeException("This should never happen. Caught: " + e);
         }
      }
   }

   public Node detach()
   {
      Element parent = getParent();

      if(parent != null)
      {
         parent.remove(this);
      }
      else
      {
         Document document = getDocument();

         if(document != null)
         {
            document.remove(this);
         }
      }

      setParent(null);
      setDocument(null);

      return this;
   }

   public String getName()
   {
      return null;
   }

   public void setName(String name)
   {
      throw new UnsupportedOperationException("This node cannot be modified");
   }

   public String getText()
   {
      return null;
   }

   public String getStringValue()
   {
      return getText();
   }

   public void setText(String text)
   {
      throw new UnsupportedOperationException("This node cannot be modified");
   }

   public void write(Writer writer) throws IOException
   {
      writer.write(asXML());
   }

   // XPath methods
   public Object selectObject(String xpathExpression)
   {
      XPath xpath = createXPath(xpathExpression);

      return xpath.evaluate(this);
   }

   public List selectNodes(String xpathExpression)
   {
      XPath xpath = createXPath(xpathExpression);

      return xpath.selectNodes(this);
   }

   public List selectNodes(String xpathExpression,
      String comparisonXPathExpression)
   {
      return selectNodes(xpathExpression, comparisonXPathExpression, false);
   }

   public List selectNodes(String xpathExpression,
      String comparisonXPathExpression, boolean removeDuplicates)
   {
      XPath xpath = createXPath(xpathExpression);
      XPath sortBy = createXPath(comparisonXPathExpression);

      return xpath.selectNodes(this, sortBy, removeDuplicates);
   }

   public Node selectSingleNode(String xpathExpression)
   {
      XPath xpath = createXPath(xpathExpression);

      return xpath.selectSingleNode(this);
   }

   public String valueOf(String xpathExpression)
   {
      XPath xpath = createXPath(xpathExpression);

      return xpath.valueOf(this);
   }

   public Number numberValueOf(String xpathExpression)
   {
      XPath xpath = createXPath(xpathExpression);

      return xpath.numberValueOf(this);
   }

   public boolean matches(String patternText)
   {
      NodeFilter filter = createXPathFilter(patternText);

      return filter.matches(this);
   }

   public XPath createXPath(String xpathExpression)
   {
      return getDocumentFactory().createXPath(xpathExpression);
   }

   public NodeFilter createXPathFilter(String patternText)
   {
      return getDocumentFactory().createXPathFilter(patternText);
   }

   public Pattern createPattern(String patternText)
   {
      return getDocumentFactory().createPattern(patternText);
   }

   public Node asXPathResult(Element parent)
   {
      if(supportsParent())
      {
         return this;
      }

      return createXPathResult(parent);
   }

   protected DocumentFactory getDocumentFactory()
   {
      return DOCUMENT_FACTORY;
   }

   protected Node createXPathResult(Element parent)
   {
      throw new RuntimeException("asXPathResult() not yet implemented fully "
         + "for: " + this);
   }
}

/*
 * Redistribution and use of this software and associated documentation
 * ("Software"), with or without modification, are permitted provided that the
 * following conditions are met:
 * 
 * 1. Redistributions of source code must retain copyright statements and
 * notices. Redistributions must also contain a copy of this document.
 * 
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 * 
 * 3. The name "DOM4J" must not be used to endorse or promote products derived
 * from this Software without prior written permission of MetaStuff, Ltd. For
 * written permission, please contact dom4j-info@metastuff.com.
 * 
 * 4. Products derived from this Software may not be called "DOM4J" nor may
 * "DOM4J" appear in their names without prior written permission of MetaStuff,
 * Ltd. DOM4J is a registered trademark of MetaStuff, Ltd.
 * 
 * 5. Due credit should be given to the DOM4J Project - http://www.dom4j.org
 * 
 * THIS SOFTWARE IS PROVIDED BY METASTUFF, LTD. AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL METASTUFF, LTD. OR ITS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 * 
 * Copyright 2001-2005 (C) MetaStuff, Ltd. All Rights Reserved.
 */
